Normal pressure hydrocephalus co-existing with a second dementia disorder

Clinical Outcomes After Ventriculo-Peritoneal Shunting in Patients With Classic vs. Complex NPH

Objective

Normal pressure hydrocephalus (NPH) is a neurological condition characterized by a clinical triad of gait disturbance, cognitive impairment, and urinary incontinence in conjunction with ventriculomegaly. Other neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and vascular dementia share some overlapping clinical features. However, there is evidence that patients with comorbid NPH and Alzheimer's or Parkinson's disease may still exhibit good clinical response after CSF diversion. This study aims to evaluate clinical responses after ventriculo-peritoneal shunt (VPS) in a cohort of patients with coexisting NPH and neurodegenerative disease.

Methods

The study has two components; (i) a pilot study was performed that specifically focused upon patients with Complex NPH and following the inclusion of the Complex NPH subtype into consideration for the clinical NPH programme, (ii) a retrospective snapshot study was performed to confirm and characterize differences between Classic and Complex NPH patients being seen consecutively over the course of 1 year within a working subspecialist NPH clinic. We studied the characteristics of patients with Complex NPH, utilizing clinical risk stratification and multimodal biomarkers.

Results

There was no significant difference between responders and non-responders to CSF diversion on comorbidity scales. After VPS insertion, significantly more Classic NPH patients had improved cognition compared to Complex NPH patients (p = 0.005). Improvement in gait and urinary symptoms did not differ between the groups. 26% of the Classic NPH group showed global improvement of the triad, and 42% improved in two domains. Although only 8% showed global improvement of the triad, all Complex NPH patients improved in gait.

Conclusions

Our study has demonstrated that the presence of neurodegenerative disorders co-existing with NPH should not be the sole barrier to the consideration of high-volume tap test or lumbar drainage via a specialist NPH programme. Further characterization of distinct cohorts of NPH with differing degrees of CSF responsiveness due to overlay from neurodegenerative or comorbidity risk burden may aid toward more precise prognostication and treatment strategies. We propose a simplistic conceptual framework to describe NPH by its Classic vs. Complex subtypes to promote the clinical paradigm shift toward subspecialist geriatric neurosurgery by addressing needs for rapid screening tools at the clinical-research interface.

Hydrocephalic Dementia: Revisited with Multimodality Imaging and toward a Unified Imaging Approach

Objective  Overlap of normal pressure hydrocephalus (NPH) and pathology proven cases of dementia is known. The objective of this paper is to correlate both the clinical and multimodality imaging findings in patients with imaging diagnosis NPH and give a hypothesis for association of clinical findings.

Methods  This is a retrospective observational analysis of 13 cases patients who were referred to molecular imaging center for imaging in 2016 to 2019, and they were divided into four groups based on structural imaging findings. Group 1 had magnetic resonance imaging (MRI) findings of diffuse effacement of sulcal spaces (DESH) and flow void, whereas Group 4 had none of these two. Group 3 had MRI findings of DESH but no flow void, and Group 2 had flow void but no DESH. Clinical presentation, MRI-PET findings of four groups are assessed.

Results  Groups with presence of flow void showed hypometabolism in the medial frontal and medial temporal lobe. Groups with presence of DESH has effacement of parietal sulci showed parietal hypo metabolism with clinical presentation AD/mixed dementia and absence of parietal effacement showed FTD-like presentation. Groups without flow void or DESH showed only mild medial temporal hypometabolism and presented with classical signs of NPH. ASL perfusion changes are in correlation with metabolism on positron emission tomography (PET)-MRI.

Conclusion  This study has led us to hypothesize the lack of outflow of brain protein and their deposition in parenchyma based on pressure gradient would be easier explanation to go with cluster of findings. MR-PET and other investigations each had different specificity and sensitivity and different pattern of presentation.

Deconstructing normal pressure hydrocephalus: Ventriculomegaly as early sign of neurodegeneration

Idiopathic normal pressure hydrocephalus (NPH) remains both oversuspected on clinical grounds and underconfirmed when based on immediate and sustained response to cerebrospinal fluid diversion. Poor long-term postshunt benefits and findings of neurodegenerative pathology in most patients with adequate follow-up suggest that hydrocephalic disorders appearing in late adulthood may often result from initially unapparent parenchymal abnormalities. We critically review the NPH literature, highlighting the near universal lack of blinding and controls, absence of specific clinical, imaging, or pathological features, and ongoing dependence for diagnostic confirmation on variable cutoffs of gait response to bedside fluid-drainage testing. We also summarize our long-term institutional experience, in which postshunt benefits in patients with initial diagnosis of idiopathic NPH persist in only 32% of patients at 36 months, with known revised diagnosis in over 25% (Alzheimer's disease, dementia with Lewy bodies, and progressive supranuclear palsy). We postulate that previously reported NPH cases with "dual" pathology (ie, developing a "second" disorder) more likely represent ventriculomegalic presentations of selected neurodegenerative disorders in which benefits from shunting may be short-lived, with a consequently unfavorable risk-benefit ratio. Ann Neurol 2017;82:503-513.

Clinical characteristics of idiopathic normal pressure hydrocephalus with Lewy body diseases

BACKGROUND

Comorbidity of idiopathic normal pressure hydrocephalus and neurodegenerative diseases presents a diagnostic challenge. The aim of this study was to elucidate the clinical features of iNPH patients who are possibly comorbid with Lewy body diseases.

METHODS

In this study, we retrospectively analyzed the records of consecutive 127 patients with definite idiopathic normal pressure hydrocephalus. (123)I-Metaiodobenzylguanidine myocardial scintigraphy was undertaken to 21 patients with idiopathic normal pressure hydrocephalus because of suspicion for comorbid Lewy body diseases.

RESULTS

As a result, 7 of the 21 patients with idiopathic normal pressure hydrocephalus exhibited cardiac sympathetic abnormality. Idiopathic normal pressure hydrocephalus patients with cardiac sympathetic dysfunction had the constellation of clinical findings, such as younger onset, less severe urinary dysfunction, kinesie paradoxale, and cogwheel rigidity.

CONCLUSIONS

Our results suggested that comorbidity of idiopathic normal pressure hydrocephalus and Lewy body diseases are not rare condition and careful screening for potentially-curative surgery is important especially in atypical cases.

Hydrocephalic Parkinsonism: lessons from normal pressure hydrocephalus mimics

Background

Hydrocephalus is an under-recognized presentation of progressive supranuclear palsy (PSP) and dementia with Lewy bodies (DLB).

Methods

We describe four normal pressure hydrocephalus (NPH)-like presentations of pathology-proven PSP (n = 3) and DLB (n = 1) and review the literature on the hydrocephalic presentation of these atypical parkinsonisms.

Results

Despite the presence of ventriculomegaly disproportionate to the extent of parenchymal atrophy, all patients demonstrated early postural impairment and/or oculomotor abnormalities that encouraged a diagnostic revision. Hallucinations were the only early atypical manifestation of the hydrocephalic DLB presentation.

Conclusions

Early postural impairment, falls, oculomotor impairment, and/or hallucinations are inconsistent with the diagnosis of NPH and suggest PSP or DLB as the underlying NPH mimic. We postulate that previously reported cases of “dual” pathology (e.g., NPH and PSP) actually represent the hydrocephalic presentation of selected neurodegenerative disorders.

Electronic supplementary material

The online version of this article (doi:10.1186/2054-7072-1-2) contains supplementary material, which is available to authorized users.

Diffusion tensor imaging in elderly patients with idiopathic normal pressure hydrocephalus or Parkinson's disease: diagnosis of gait abnormalities

BACKGROUND

Gait abnormalities in the elderly, characterized by short steps and frozen gait, can be caused by several diseases, including idiopathic normal pressure hydrocephalus (INPH), and Parkinson's disease (PD). We analyzed the relationship between these two conditions and their association with gait abnormalities using laboratory test data and findings from diffusion tensor imaging (DTI).

METHODS

The study involved 10 patients with INPH, 18 with PD, and 10 healthy individuals (control group). Fractional anisotropy (FA) of five brain areas was measured and compared among the three groups. In addition, the association of INPH and PD with gait capability, frontal lobe function, and FA of each brain area was evaluated.

RESULTS

The INPH group had significantly lower FA for anterior thalamic radiation (ATR) and forceps minor (Fmin) as compared to the PD group. The gait capability correlated with ATR FA in the INPH and PD groups. We found that adding DTI to the diagnosis assisted the differential diagnosis of INPH from PD, beyond what could be inferred from ventricular size alone.

CONCLUSIONS

We expect that DTI will provide a useful tool to support the differential diagnosis of INPH and PD and their respective severities.